![Mechanisms that contribute to dust growth just beyond the snow line. Many-seed icy aggregates grow in the outer disk’s regions due to the high sticking efficiency of water ice and disintegrate as they cross the water snow line (green-to-blue interface) into silicate monomers and water vapor. Both diffuse back across the snow line due to turbulence, facilitating further accumulation of icy water and the growth of icy aggregates just behind the snow line, effects found in our numerical model as well (see Figs. 7 and E.2).-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Hydrodynamics.png?fit=1200%2C683&ssl=1)
[astro-ph.EP] Aims. We investigated the properties of the water snow line during the early stages of disk evolution, paying particular attention to the effects of gravitational instability and dust growth on the snow line’s shape and position.
Methods. We used the FEOSAD numerical hydrodynamics code to simulate the disk formation and evolution in the thin-disk limit. The simulations incorporate the coevolution of gas, dust, and volatiles, including dust growth, volatile phase transitions, and dust-size-dependent opacities.
Results. The position of the water snow line is highly nonsteady during the considered disk evolution period, first moving outward during the disk build-up and then retreating back as the disk cools. Its form in the disk midplane deviates strongly from a circular shape in the early gravitationally unstable phase of disk evolution.
An increase in the amounts of grown dust and water ice as well as in the maximum dust size just beyond the snow line, as is readily observed in one-dimensional viscous disk evolution models, in our hydrodynamic models occurs only after gravitational instability diminishes.
Dust-growth-induced opacity changes have a profound effect on the position of the water snow line, shifting it closer to the star by almost a factor of two compared to models that do not take this effect into account.
Conclusions. The shape, position, and properties of the water snow line in young, gravitationally unstable disks differ from those of older, axisymmetric disks. Our results highlight the importance of taking into account the dependence of opacity on dust size when studying disk evolution.
Eduard I. Vorobyov (1,2), Anastasiia Topchieva (3), Aleksandr Skliarevskii (2), Yaroslav Pavlyuchenkov (3), Konstanze Zwintz (1) ((1) Institut fuer Astro- und Teilchenphysik, Universitaet Innsbruck, Innsbruck, Austria, (2) Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia, (3) Institute of Astronomy, Russian Academy of Sciences, Pyatnistkaya str., Moscow, Russia)
Comments: Accepted for publication in Astronomy & Astrophysics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2608.17921 [astro-ph.EP] (or arXiv:2608.17921v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2608.17921
Focus to learn more
Related DOI:
https://doi.org/10.1051/0004-6361/202660970
Focus to learn more
Submission history
From: Eduard I. Vorobyov
[v1] Tue, 18 Aug 2026 15:45:47 UTC (7,915 KB)
https://arxiv.org/abs/2608.17921
astrobiology, exoplanet,
